Surgical retractor system

ABSTRACT

A surgical retractor system having a frame and a plurality of arms connected thereto is disclosed. At least one arm is moveable relative to the frame and the relative movement is constrained to a direction along the longitudinal axis of the arm. At least one retractor blade is removably connected to each of the plurality of arms. The blade is fixably rotatable about an axis normal to the longitudinal axis of the arm to which it is connected.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/422,511 filed on Jun. 6, 2006, now issued as U.S. Pat. No. 7,935,053,which is herein incorporated in its entirety by reference.

FIELD OF THE INVENTION

The invention generally relates to devices and methods that improvesurgical procedures by, for example, providing a working space for theprocedure and improving the surgical conditions for the practitioner ofa procedure.

BACKGROUND OF THE INVENTION

In surgical procedures generally, surgeons try to keep incisions assmall as possible to minimize or reduce trauma to the patient and damageto tissue. However, it is usually necessary that the surgeon have aclear view of the operating field. Also, an opening may need to beenlarged to accommodate the passing of medical implants therethrough.

In the field of spine surgery, there is an increasing interest indeveloping minimally invasive methods, as opposed to conventional “open”spine surgery. The goals of these less invasive alternatives are toavoid the surgical exposure, dissection, and retraction of muscles andtissues that is necessary with “open” surgery. In general, a minimallyinvasive spine surgery system should be able to perform the sameprocedure as the traditional open technique, but through smallerincisions. As a result, some physicians feel that using a minimallyinvasive spine surgery system generally causes less soft tissue damage,reduces blood loss and reduces recovery time. In addition, patientsgenerally prefer the smaller scars that are left using a minimallyinvasive approach.

A variety of retractors are available for use in surgical operations toreposition muscular tissue, vessels, nerves, and other tissue with theaid of retractor blades, thereby providing access to the site of theoperation. Surgical retractors are particularly important in performingsurgical procedures that involve the spinal column, where access to thesurgical site can be obtained through a posterior, anterior, lateral, orcombined approach.

Many current retractors have several shortcomings. For example, mostcurrently available retractors are large and cumbersome, requiring along incision length that traumatizes the patient's muscles and tissue.Also, some current retractors provide so much variability andadjustability that they are unwieldy, fiddly, and/or difficult to adjustor maneuver and are simply impractical for use in a typical surgicalenvironment. However, other retractors may not provide sufficientadjustability. For example, some retractors do not allow independentpivoting of an individual retractor blade, while others may only providefor retraction of coupled pairs of blades as opposed to independentretraction, and still others may only allow for finite adjustmentconstrained to a rack and pinion system or a predefined arc forpivoting.

Therefore a need exists for a retractor system that overcomes orminimizes these and other problems.

SUMMARY OF THE INVENTION

Embodiments of the invention are generally directed toward a surgicalretractor system having a frame and a plurality of arms connectedthereto. In one embodiment, at least one arm is moveable relative to theframe and the relative movement is generally constrained to a directionalong the longitudinal axis of the arm. At least one retractor blade isremovably connected to each of the plurality of arms. In one embodiment,each blade is fixably rotatable about an axis normal to the longitudinalaxis of the arm to which it is connected.

In one embodiment, the system includes at least four arms and at leastone arm is fixed relative to the frame. In another embodiment, aplurality of arms are moveable relative to the frame, and wherein therelative movement of each moveable arm is constrained to a directionalong the longitudinal axis of the arm, and wherein each moveable arm isindependently moveable relative to the frame.

According to another embodiment, a bar clamp mechanism is connected tothe frame and associated with at least one moveable arm to releasablyclamp the moveable arm in a fixed position relative to the frame. In oneembodiment, each moveable arm is non-threadedly connected to the frameand is actuatable by a manual retraction tool. In another embodiment,the longitudinal axes of the arms are coplanar. In another embodiment,the longitudinal axes do not rotate about frame.

According to one embodiment, the frame has a generally polygonal shape.In another embodiment, each of the moveable arms is selectably slidablewith respect to the frame. According to another embodiment, the systemcomprises at least four retractor blades. In another embodiment, theblades comprise an elongate body having an inner face and an outer faceand a longitudinal axis extending from a proximal end to a distal end,the inner face being generally concave and the outer face beinggenerally convex. In another embodiment, a flexible sleeve at leastpartially surrounds the retractor blades. In an alternative embodiment,the flexible sleeve is made from a polyurethane rubber material.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more readily understood with reference to theembodiments thereof illustrated in the attached figures, in which:

FIG. 1 is a perspective view of one embodiment of a retractor systemaccording to the present invention positioned adjacent a bone model by asurgical arm;

FIG. 2 is a top perspective view of one embodiment of a retractor systemaccording to the present invention shown in a first position;

FIG. 3 is a bottom perspective view of the retractor system of FIG. 2;

FIG. 4 is a top perspective view of another embodiment of a retractorsystem according to the present invention shown without retractorblades;

FIG. 5 is a bottom perspective view of the retractor system of FIG. 4;

FIG. 6 is a perspective view of various embodiments of retractor bladesaccording to the present invention;

FIGS. 7-8 are partial cross-sectional views of a retractor systemaccording to the invention showing a sleeve member assembled on theretractor blades;

FIG. 9 is a top perspective view of one embodiment of a retractor systemaccording to the present invention shown in a second position;

FIG. 10 is a bottom perspective view of the retractor system of FIG. 9;

FIGS. 11-12 are perspective views of one embodiment of a retraction toolin operation with a retractor system according to the present invention;

FIG. 13 is a top perspective view of one embodiment of a retractorsystem according to the present invention shown in a third position;

FIG. 14 is a bottom perspective view of the retractor system of FIG. 13;

FIG. 15 is a perspective view of one embodiment of an arm assemblyaccording to the invention shown in a first position;

FIG. 15A is a cross-sectional view of FIG. 15 taken along line 15A;

FIG. 16 is a perspective view of one embodiment of an arm assemblyaccording to the invention shown in a second position;

FIG. 16A is a cross-sectional view of FIG. 16 taken along line 16A;

FIG. 17 is an enlarged sectional view of a portion of one embodiment ofan arm assembly according to the invention; and

FIG. 18 is an exploded view of another embodiment of a surgicalretractor system according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the invention will now be described. The followingdetailed description of the invention is not intended to be illustrativeof all embodiments. In describing embodiments of the present invention,specific terminology is employed for the sake of clarity. However, theinvention is not intended to be limited to the specific terminology soselected. It is to be understood that each specific element includes alltechnical equivalents that operate in a similar manner to accomplish asimilar purpose.

The terms “first position,” “second position,” and “third position,” asused herein, merely refer to dissimilar positions and are not meant toimply that all embodiments can only be adjusted to one, two, or threepositions. In some embodiments, a retractor system may be adjustable toa finite number of positions. In other embodiments, the distance betweenone or more components can be increased or decreased to any desiredextent, thereby allowing a retractor system to adjust to an almostinfinite number of positions.

Referring to FIG. 1, one embodiment of a retractor system 100 accordingto the invention is shown. The retractor system 100 includes a frame 102that is attachable to an arm 104. Arm 104 may be attached to asupporting structure 105, which may comprise, for example, a table, arack, a cart, or the like. In one embodiment, arm 104 is a surgical arm,such as a universal arm, which includes enough joints to provide adesired number of degrees of freedom to easily adjust frame 102 over anincision in a patient. The joints of arm 102 can include either amechanism or a certain stiffness that allows the surgeon to position thesurgical arm easily to a desired position and maintain the surgical armand retractor system 100 in the new position. Utilizing and moving arm104 allows frame 102 to be positioned in a substantially stationaryposition over the surgical access site. Frame 102 may provide a workingsupport for the surgeon to rest his/her hands or arms on whileperforming a surgical procedure.

As shown in FIGS. 2-3, retractor system 100 generally comprisesretractor blades 110 that may be removably attached to frame 102. In oneembodiment, retractor blades 110 may be attached to the inside of frame102. Once frame 102 is positioned over an incision, such as a smallminimally invasive incision, each surgical retractor blade 110 may beinserted into a body cavity through the incision. The retractor blade(s)110 can also create or increase the size of a body cavity throughinsertion and/or retraction.

The retractor blade(s) 110 may be movably attached to positioning meansor arms 120, 122. Each arm 120 provides the ability to independentlychange the position of a surgical retractor blade 110 and can be changedby a translation in an X and/or Y direction and/or a rotation about ahorizontal or X-Y plane. According to one embodiment, arms 120 tightlyfit within and are slideable with respect to openings 140. In operation,arms 120 may translate in a horizontal or X-Y plane when a force isapplied to force the arms 120 in an outwardly direction. To hold arms120 in a desired position, a bar clamp mechanism 142 or other fixingmeans, such as a screw, a latch, or the like, may be used. Such a barclamp configuration is advantageous when compared to a threadedretraction arrangement since threads are not forced to do the retractionwork and thus eliminating the possibility of cross threading. Accordingto one embodiment, one fixed arm 122 may be provided that is fixed inthe X-Y direction such that a blade 110 attached to arm 122 is nottranslatable in the X-Y direction, however, a blade attached thereto maystill be rotatable about a horizontal or X-Y plane.

In general, each positioning arm 120, 122 extends along a longitudinalaxis 123 from a proximal end 124 to a distal end 126. The distal end 126includes a pivot member 128 to which a retractor blade 110 may beattached, whereby the pivot member is fixably rotatable about a pivotaxis 129 extending transverse to the longitudinal axis 123. The term“fixably rotatable,” as defined herein means that a pivot member is,alternatively, fixed or rotatable, about a pivot axis. The foregoingconfiguration provides flexibility in manipulating the operating fieldin the patient.

The pivot members 128 of arms 120, 122 may include attachment means 130that may be used to attach retractor blade 110 to system 100. Theattachment means 130 can be any type of means that enables attachment,such as a screw, pin, magnet or the like. Other examples of suitableconnectors include clips, hinges, rivets, adhesives, tressits, or thelike. In further embodiments, a retractor blade may be attached to,and/or extend from, a frame component. In one embodiment, the attachmentmeans 130 comprises a dovetail groove 132 which facilitates connectionand disconnection of the retractor blade 110 to and from the frame,respectively. In one variation, the dovetail groove 132 is open at thetop to facilitate top loading of blades 110 and comprises a pin 134protruding outward from the surface of groove 132 to locate and or stopthe blade 110 in the vertical or Z direction. Various lengths and shapesof blades may be provided to accommodate surgical procedures at variousdepths subcutaneously. The attachment means is secure enough to keep thesurgical retractor blades 110 attached to the arms 120, 122 while thesurgical retractor blades undergo force or torque during retraction. Inone embodiment, a pivotable cover 136 is provided to prevent the backout of blades 110 with respect to pivot member 128. In operation, cover136 may be pivoted in place to cover the proximal end of a blade 110 tohold it in place in the longitudinal or Z direction with respect topivot member 128.

In one embodiment, frame 102 comprises a generally diamond shaped frame.However, in alternate embodiments the frame can take any shape, such aselliptical, polygonal, or circular, as long as it is able to provide abase for the retractor blades 110. Examples of suitable materials ofconstruction for the various portions of the retractor systems accordingto the invention include metals and metal alloys (e.g., stainless steel,aluminum, titanium, nitinol, cobalt chrome, etc.) and/or plastics (e.g.,carbon fiber reinforced polymer (CFRP), ultra-high molecular weightpolyethylene (UHMWPE), ultem, radel, vectra, polycarbonate, etc.).

In particular embodiments, the number of retractor blades 110 may be twoor more. In one embodiment, four retractor blades 110 are provided. Ingeneral, each retractor blade has an inner face, an outer face, and alongitudinal axis running the length of the blade from a proximal end111 to an opposite distal end 112. In one embodiment, the retractorblades 110 have a curved or partial cylindrical shape, such that whenblades 110 are aligned adjacent one another, a cylinder, channel,cannula, or the like is created. The size of the retractor blades 110 isdependent on the type of surgical procedure. For delicate procedures,small or miniature blades may be used, while for macroscopic procedures,blades that are less constrained in size may be used. The retractorblades 110 may be made of any material suitable for surgical proceduresknown to those skilled in the art. The blades 110 can be elongated andcurved. In general, any type of surgical retractor blade 110 can be usedas are common in the art. Also, the type, size, and shape of surgicalretractor blades 110 can be mixed together as well as changed or renewedduring a surgical procedure. Referring to FIG. 6, non limiting exemplaryalternative embodiments are shown, where the distal end 112 may beangled or contoured. In this regard, blades 110 may accommodateparticular anatomical features as required depending on the procedureinvolved.

Referring to FIGS. 7-8, in one embodiment, a flexible sleeve 135 may beprovided to surround the retractor blades 110 to prevent body tissuefrom intruding into the space created by the retractor blades once theyare retracted. In general, sleeve 135 may be initially assembled on thedistal end of blades 110 in a rolled-up position as shown in FIG. 7.Sleeve 135 may then be extended or unrolled in a proximal direction tosurround a substantial portion of blades 110. In one embodiment, sleeve135 may be made from a polyurethane rubber material, however,alternative appropriate materials known to those skilled in the art mayalso be used. In general, sleeve 135 is substantially resilient suchthat as blades 110 are moved and/or retracted, sleeve 135 accommodatesblade movement while substantially surrounding blades 110 to preventbody tissue from intruding into the space created by the retractorblades once they are retracted. In this regard, sleeve 135 helps toprovide a clean unimpeded field of vision for a surgeon utilizingretractor system 100.

The position of each retractor blade 110 can be changed independent fromthe other retractor blades, which allows a great amount of flexibilityto the surgeon to explore an operating field. Furthermore, the positionof each retractor blade 110 can be changed without changing the positionof the frame 102. In other words, the frame may remain in asubstantially stationary and fixed position over the incision. In thisregard, a change in the operating field can be obtained by changing theposition of one or more retractor blades 110.

Referring to FIGS. 11-12, a handheld retraction tool 150 may be furtherprovided to assist a surgeon in retracting, or moving in an outwardlydirection, an arm 120 and, a retractor blade attached thereto. In oneembodiment, best seen in FIG. 17, a spring 152 biases or pushes latchmember 154 against arm 120 to prevent inadvertent inward movement of anarm once it has be retracted outward. In one embodiment, as shown inFIGS. 11-12, tool 150 may engage slot 153 in frame 102 and an innerportion of a retraction blade 110 to translate a blade 110 in an outwarddirection. In this regard, a surgeon may independently actuate a blade110 while maintaining tactile feed back through the retraction tool 150.

As explained above, in some embodiments, rotation of blades 110 aboutthe X-Y plane can be achieved by pivoting pivot members 128 about pivotaxes 129. As best seen in FIGS. 15-16, one example of a pivotingmechanism is shown. Pivoting adjustment nut 160 comprises a hollowinternal portion with an internally threaded section that engages anexternally threaded pivot rod 162. Rod 162 is pivotally attached to arm120, 122 at a position spaced from pivot axis 129. Nut 160 is freelyrotatable with respect to pivot member 128 yet fixed in the longitudinalor Z-direction with respect to member 128. In operation, when nut 160 isrotated a moment arm around pivot axis 129 is created, causing blade 110to pivot with respect to arm 120, 122. Rotation of nut 160, enables arotation about the pivot axis to establish toe-out or toe-in ofretractor blade 110. As one skilled in the art will appreciate, thereare different ways and techniques to establish these rotations andtranslations, which are all included as possible positioning means forthe purpose of this invention. Therefore, these examples should beregarded as illustrative rather than limiting to the scope of thepresent invention.

According to one aspect of the aforementioned pivot arrangement, pivotmember 128 is connected adjacent the proximal end of blade 110 and pivotmember 128 is positioned adjacent the distal tip of arms 120, 122. Oneskilled in the art may appreciate that utilizing this configuration, theproximal end of blade 110 advantageously moves along a relatively smallradius when blade 110 is pivoted which allows greater vision of theworking end or distal end of the blades since a wider diameter portal oropening may be achieved at the proximal end of blades 110.

Referring again to FIGS. 1-3 and 9-14, in general, the inner faces ofthe retractor blades define a conduit when the retractor system is atone or more positions. In some embodiments, the conduit is substantiallycylindrical or substantially elliptical. Optionally, one or moreretractor blades contact each other when the retractor is at one or morepositions, such as for example in a first position shown in FIGS. 1-3.In still more embodiments, at least some portion of the retractor blades(e.g., the distal ends of one or more blades) provide access to asurgical site when the blades are partially or fully expanded, such asfor example in a second or third position as shown in FIGS. 9-10 or13-14, respectively. FIGS. 9-10 show an embodiment of a retractor systemin an exemplary second position where all four retractor blades 110 areparallel in the vertical direction and separated or retracted outward.FIGS. 13-14 show an embodiment of a retractor system in an exemplarythird position where all four retractor blades 110 are positioned in asimilar manner with their toes or distal ends 112 pointed outward. Oneskilled in the art will appreciate that there are an innumerable amountof positions that may be achieved and that the positions shown in FIGS.1-3, 9-10, and 13-14, are merely shown for the purpose of illustrationand should not be considered as limiting the scope of the invention. Thenumber of combinations of translation(s) and/or rotation(s) of one ormore retractor blades provides extensive flexibility to the surgeon oruser in exploring the desired operating field with a simultaneous effortto minimize the trauma and size of the incision.

As will be appreciated by skilled practitioners, a retractor system suchas those described herein may be particularly useful for lumbar spinalsurgery with either an anterior, posterior, or anterolateral approach.In one variation, the blades of the retractor system may be placedthrough the paraspinous muscle using a small sequential dilator withoutcutting any muscle or underlying fascia. The retractor system can beplaced over the sequential dilator, which has created a working channelfor the retractor system. Yet another example of use for the retractorrelates to brain surgery and vascular surgery where access space issmall or sensitive.

Some embodiments include methods of performing surgical procedures onthe spine of a human using an embodiment of a retractor system of thepresent invention. According to one method, a patient may be positionedon a table and imaging or fluoroscopy may be utilized to target asurgical site. A lateral table rail may be provided for subsequentplacement of a rigid arm assembly, such as arm 104 shown in FIG. 1.

Once a surgical site has been targeted, a longitudinal incision may bemade slightly larger than the retractor system 100 of the invention whenin a collapsed or closed position, as shown in FIGS. 2-3. In someembodiments, only the skin may be cut since sequential dilators may beused to pierce and dilate the fascia.

Once the incision is made, a dilator may be inserted into the incisionto dilate the fascia and/or paravertebral muscle tissue down to thelaminar level. Once the incision has been dilated, a retractor system100 of the invention may be directed to the surgical site. According tosome embodiments, the retractor system 100 is assembled before it isdirected to the surgical site. One or more rigid arms 104 may beattached or secured to retractor system 100. Arm 104 may be secured tothe surgical table and is attached to frame 102. Arm 104 can be adjustedduring the surgical procedure, thereby allowing a practitioner of theinvention to direct system 100 to a desired position.

Once retractor system 100 has been inserted into an incision, blades 110can be expanded using a retraction tool, such as tool 150 illustrated inFIGS. 11-12. Each blade 110 may be retracted in the cephlad-caudaland/or the medial-lateral directions independently by inserting a partof retraction tool 150 into the slot 153 of frame 102 and another partof tool 150 adjacent the interior of a particular blade to be retractedand squeezing the handle of instrument 150 to the desired extent. Asbest seen in FIG. 17, the bar clamp mechanism 142 associated with eachmoveable arm 120 allows the arm 120 to move in one direction such thatrelease of the handle of tool 150 instantaneously locks the arm at thatposition. In this regard, bar clamp 142 allows for infinite adjustmentand will hold each arm 120 at the precise expanded position as desired.Blades 110 may also be independently rotated or angled about the distalend of each arm 120, 122 as desired by actuating pivot member 128 byturning nut 160. According to one embodiment of a method of the presentinvention a flexible sleeve may be provided to substantially surroundblades 110 to prevent tissue creep or intrusion into the retracted spaceor surgical conduit created by the retraction of system 100.

In some embodiments, an illuminated surgical conduit may be created. Inone embodiment, a light source, such as for example a thin strip light,may be provided along the interior of one or more blades 110 and may beconfigured to emit light towards the distal end of the blades 110. Thelight source may be in photonic communication with an array of fiberoptic wire to power and/or control the light source. In alternateembodiments, fiber optic cable itself may be positioned along orembedded within one or more blades to emit light into the surgicalconduit. In some embodiments, an optical interface may be providedadjacent the proximal end of blades 110 to facilitate modularinterconnectivity of blades 110 while maintaining the integrity of theoptical communication from a power source to the light source.

Referring to FIG. 18, one embodiment of a fixed diameter retractorsystem 180 according to the invention is shown. In general, retractorsystem 180 comprises a tubular member 182 that is removably coupleableto a frame member 184. According to one embodiment, tube 182 has agenerally cylindrical shape with a substantially fixed diameter. Inalternate embodiments, when viewed in cross-section tube 182 may havealternative shapes as desired, including but not limited to triangular,rectangular, trapezoidal, or other polygonal shapes as well aselliptical, complex curves, and figure eight shapes. As shown in FIG.18, one or more slits 186 may be provided adjacent the proximal end 187to accommodate slight contraction to facilitate removable connectivityto frame member 184. In this regard, according to one embodiment tube182 may be snappably connected to frame member 184 adjacent proximal end187. In some embodiments, tube member 182 may have a contoured or angleddistal end 189 to accommodate particular anatomical features at asurgical site among other things. In particular embodiments, framemember 184 may include an extension 191 to connect to a surgical arm,such as arm 104 shown in FIG. 1. In this regard, retractor system 180may be moved adjacent a surgical access site and subsequently positionedin a substantially stationary position over the surgical access site inmuch the same way as system 100, described above. Frame member 184 mayprovide a working support for the surgeon to rest his/her hands or armson while performing a surgical procedure.

In some embodiments, the retractor system may include one or morefeatures that facilitate the support of one or more surgicalinstruments. Non-limiting examples of surgical instruments may include alight source (e.g., a surgical light), a suction device (e.g., a suctiontube), a tissue cutting and evacuation instrument (e.g., a device forcutting and removing disk material, such as a pituitary, or a device forcutting and removing bone material, such as a ronguer), or othersurgical instruments known in the art.

While the invention herein disclosed has been described with referenceto specific embodiments and applications thereof, numerous modificationsand variations can be made thereto by those skilled in the art withoutdeparting from the scope of the invention as set forth in the claims.

What is claimed is:
 1. A surgical retractor system, comprising: asubstantially rigid frame having an upper surface and a lower surface,the substantially rigid frame defining a horizontal plane; a pluralityof arms connected to the frame, each arm having a longitudinal axisextending from a proximal end to a distal end, wherein at least one armis moveable relative to the frame, and wherein the relative movement isconstrained to a direction along the longitudinal axis of the arm; and abar clamp mechanism received within the frame and associated with atleast one arm to releasably clamp the arm in a fixed position relativeto the frame, wherein the bar clamp mechanism includes a latch memberand a biasing member, the latch member is biased in a first position toclamp the aim in a fixed position relative to the frame and is notbiased in a second position to allow the arm to move relative to theframe, wherein at least a portion of the latch member extends beyond theframe allowing direct actuation of the latch member from the firstposition to the second position and wherein a majority of the latchmember is positioned within the frame between the upper surface and thelower surface of the frame, and wherein the frame includes an openingextending from the upper surface to the lower surface providing accessto the latch member allowing actuation of the latch member from thefirst position to the second position through the use of a manualretraction tool.
 2. The system of claim 1, further comprising at leastfour arms, wherein at least one arm is fixed relative to the frame. 3.The system of claim 2, wherein a plurality of arms are moveable relativeto the frame, and wherein the relative movement of each moveable arm isconstrained to a direction along the longitudinal axis of the arm, andwherein each moveable arm is independently moveable relative to theframe.
 4. The system of claim 3, wherein each moveable arm isnon-threadedly connected to the frame and is actuatable by the manualretraction tool.
 5. The system of claim 1, wherein longitudinal axes ofthe arms are coplanar.
 6. The system of claim 1, wherein thelongitudinal axes do not rotate about frame.
 7. The system of claim 1,wherein the frame has a generally polygonal shape.
 8. The system ofclaim 1, wherein each of the moveable arms is selectably slidable withrespect to the frame.
 9. The system of claim 1, comprising at least oneretractor blade coupled to one of the plurality of arms.
 10. The systemof claim 9, wherein the at least one retractor blade comprises anelongate body having an inner face and an outer face and a longitudinalaxis extending from a proximal end to a distal end, the inner face beinggenerally concave and the outer face being generally convex.
 11. Thesystem of claim 9, further comprising a flexible sleeve at leastpartially surrounding the retractor blades.
 12. The system of claim 11,wherein the flexible sleeve is made from a polyurethane rubber material.13. A surgical retractor system, comprising: a substantially rigid framedefining a horizontal plane, wherein the frame includes an upper surfaceand a lower surface, a plurality of arms connected to the frame, eacharm having a longitudinal axis extending from a proximal end to a distalend, wherein at least one arm is moveable relative to the frame, andwherein the relative movement is constrained to a direction along thelongitudinal axis of the arm, and a bar clamp mechanism received withinthe frame and associated with at least one arm to releasably clamp thearm in a fixed position relative to the frame, wherein the bar clampmechanism includes a latch member and a biasing member, the latch memberis biased in a first position to clamp the arm in a fixed positionrelative to the frame and is not biased in a second position to allowthe arm to move relative to the frame, wherein the frame includes anopening located above the latch member providing access to the latchmember allowing actuation of the latch member from the first position tothe second position through the use of a manual retraction tool, whereina majority of the latch member is positioned within the frame betweenthe upper surface and the lower surface of the frame.
 14. The system ofclaim 13, wherein the system includes at least three arms.
 15. Thesystem of claim 13, wherein the system includes at least four arms. 16.The system of claim 13, wherein at least one blade is connected to theframe via a dovetail groove.
 17. The system of claim 13, wherein a bladeis attached to at least one of the arms, wherein the at least one arm ismovable longitudinally in an X-Y plane and the blade is pivotable aroundthe X-Y plane.
 18. The system of claim 17, wherein the blade ispivotable via a rotatable nut.
 19. The system of claim 18, wherein therotatable nut is positioned on an upper surface of at least one of thearms.